This document claims priority to French application number 0106390 filed May 15, 2001, the entire content of which is hereby incorporated by reference.
The invention relates to a device for packaging and dispensing a product, such as a liquid or small/fine powder, in a spray. More particularly, the invention relates to a miniature spray, which is preferably disposable and suitable with packaging for cosmetic product samples, such as perfumes or products for protecting against the harmful rays of the sun. The product is preferably a liquid product, but may also be in the form of a small particle size powder.
Cosmetic sample or spray type dispensers are known as shown, for example, in FR-A-2 778 639, EP-A-0 761 314, FR-A-2 443 980, or in U.S. Pat. No. 3,897,005 or U.S. Pat. No. 3,412,907. These devices suffer principally from at least one shortcoming associated with their cost of manufacture, difficulty to use, or poor quality of the spray they are capable of generating.
Because samples are not generally intended for sale, their cost of manufacture must be as low as possible. It is thus important to utilize devices formed of components that can be easily mass produced and that can be assembled in a simple manner. Moreover, the devices must be capable of generating a high quality spray to the extent possible, particularly in terms of providing constant or consistent spray characteristics.
U.S. Pat. No. 4,328,912 describes a container for dispensing a product. With this arrangement, a part of the container located in the vicinity of the outlet forms a valve consisting of a hemisphere which is squeezed in order to selectively close off the passage leading to the outlet. An inverse pressure is then applied to the valve to restore the hemispherical shape and permit the product to exit in response to pressure exerted on the walls of the container. A significant problem arising from a configuration of this type lies in the fact that, when the product is dispensed the volume of the dispensed product is replaced by a corresponding volume of air. Therefore, unless the device is turned upside down, the exit of the product, particularly in spray form, becomes increasingly difficult to generate in subsequent uses. Particularly, in the cosmetics field, this upside down dispensing can be most unsuitable and most awkward.
U.S. Pat. No. 5,332,121 and U.S. Pat. No. 5,156,300 describe devices with a flexible pouch arranged inside a compressible container, with the product disposed inside of the flexible pouch. Such devices are suitable for condiments such as ketchup, and thus have no intention or purpose in dispensing the product in a spray form. The products to be dispensed are very viscous and the outlets have a diameter such that even if it were desired (which is not generally the case with ketchup, mustard or mayonnaise) dispensing of the product in a spray form would be impossible to achieve.
It is an object of the invention to provide a spray device that solves at least some, preferably all, of the problems discussed above with reference to conventional devices.
In particular, it is an object of the invention to provide a device which is easy to mass produce and which is inexpensive to manufacture.
It is a further object of the invention to provide a device which makes it possible to generate a spray of not only satisfactory quality, but also a quality that is consistent and can be reproduced from one device to the next.
Additional objects and advantages will become apparent in the following detailed description. According to one aspect of the invention, a device for spraying a fluid product, such as a cosmetic product, is provided. The device includes a reservoir containing the product substantially at atmospheric pressure. The reservoir has at least one, preferably plural flexible walls, with the walls preferably formed such that they are substantially without shape memory. The device is also equipped with a dispenser head, preferably a spray element for spraying the product in response to a pressure exerted on the flexible walls of the reservoir. An anti-air-intake element is provided in order to prevent entry of air inside the reservoir when the application of pressure ceases.
As used herein, xe2x80x9csprayxe2x80x9d is to be understood to mean the projection of fine droplets or particles in the form of a mist or cloud. Typically, the average size of the particles or of the droplets is preferably no more than 1 mm. More preferably, the particles or droplets are at most on the order of a few hundred xcexcm in size, and even more preferably, the particles or droplets are in the range from 5 xcexcm to 200 xcexcm in size.
The substantial absence of shape memory in the flexible walls of the container reflects the fact that, when the pressure for generating the exit of the product ceases, the walls remain substantially in their deformed form or condition and do not tend to resume the form they had before pressure was exerted. This characteristic distinguishes the container used according to the invention from conventional containers. In particular, prior containers have been provided in the form of bottles or tubes, for example, containers made from polyethylene, in which the walls can be deformed in order to force the product out of the container via an outlet. With these containers, when the pressure on the walls ceases, the walls have a natural tendency, because of their elasticity to substantially resume the form they had before they were deformed. As a result, air is sucked into the container in order to compensate for the increase in volume of the container. Although the container or reservoir walls of the invention are preferably formed of a material that has no shape memory or little elasticity, even if formed of a material that is elastic or has shape memory, because air is prevented from entering into the container after a spray dispensing operation is completed, the walls of the container will be maintained in a deformed state or an at least partially deformed state. As a result, the next spray operation will provide a consistent good quality spray because the spray will not be interrupted or diminished by air in the container, even if the container is held upright during the subsequent spray operation. By contrast, if substantial amounts of air were allowed to enter the container, the next spraying operation would start with only air being forced from the container and/or dispensing of the product would be inconsistent or interrupted by air. Also, by minimizing the amount of air in the container, pressure exerted upon the container is more rapidly utilized to force the product from the container rather than to compress air inside of the container or to force air from the container.
The spray element of the invention, also known as a diffuser or diffusion head, includes a structure in the form of a nozzle traversed by at least one orifice through which the product is sprayed in the form of a mist or cloud of reasonably fine droplets. There are various types of nozzles that can be utilized, some including one or more swirl or swirling channels capable of accelerating the liquid upstream of the outlet so as to produce still finer particles of liquid. Typically, the orifice via which the product is sprayed has a diameter from 0.2 mm to 1 mm, and preferably from 0.2 mm to 0.7 mm.
According to one of the advantageous characteristics of the invention, by arranging for the product to occupy all or practically all the container during filling, pressure exerted on the flexible walls of the container is transmitted practically in its entirety to the product, such that the product then passes via the diffuser and is sprayed in the manner described above. There is thus little or no loss of charge due to air and no loss of efficiency in spraying the product. Dispensing of the product in spray form is thus easy to achieve, regardless of the level of product remaining in the container and also regardless of the position of use.
With the arrangement of the invention, when pressure on the walls of the container ceases, the absence or practical absence of shape memory of the material forming the container, in combination with the anti-air-intake element which prevents entry of any substantial quantities of air inside the container, means that the device is virtually always in a configuration in which the product occupies substantially the entire volume of the container. Thus, when the consumer presses again on the walls of the container, spraying is immediate.
Preferably, the device is configured such that the actuating pressure is applied directly to the walls of the container, and the inner surface of the walls are in contact with the product to be sprayed. Accordingly, the inertia of the system and inefficiencies are largely reduced. Therefore dispensing, particularly in spray form, is facilitated, especially when the product is to be dispensed by pressure transmitted suddenly to the product.
The flexible walls may be formed from at least one layer of a thermoplastic or metallic material, or from a multi-layer complex based on such materials, with the reservoir configured in the form of a tube, a pouch or a sachet. Preferably, the container is configured in the form of a sachet formed by the superposition of two sheets adhesively bonded or welded along their peripheral edges.
The anti-air-intake element can be configured in the form of a valve opening in a single direction so as to allow the exit of the product in response to pressure inside the reservoir while opposing any entry of air inside the reservoir when said pressure ceases.
A one-way valve of this type can be produced from a thermoplastic or cross linked elastomer, such as silicone, natural or synthetic latex, EPDM, polyurethane or flexible polyvinyl chloride (PVC).
The valve element that opens in one direction can be in the form of a single piece element with the nozzle, which enhances fitting and positioning. Alternatively, the nozzle and the valve may be formed from two or more different pieces, for example, made from different materials.
The diffuser can be fitted onto the reservoir or container by adhesive bonding or welding, preferably with the use of heat.
The device according to the invention is particularly advantageous for packaging and spraying of a sample measure of a cosmetic product, such as a perfume or a product for protecting against the harmful rays of the sun. Although particularly advantageous for cosmetic or skin care products that are in liquid form, as noted earlier, the device can also be used for dispensing other products such as products that are in a powder form. Also, although the invention is particularly advantageous for product samples due to the simplicity in use and manufacture (low cost), aspects of the invention could also be advantageously utilized in typical consumer product sized containers.
Apart from the arrangements described above, it is to be understood that various aspects of the invention can be utilized in various forms or types of containers. Arrangements are described below as non-limiting illustrative embodiments.